The genetic lineage of Europe mysteriously transformed about 4,500 years ago, new research suggests.

The findings, detailed today (April 23) in the journal Nature Communications, were drawn from several skeletons unearthed in central Europe that were up to 7,500 years old.

"What is intriguing is that the genetic markers of this first pan-European culture, which was clearly very successful, were then suddenly replaced around 4,500 years ago, and we don't know why," said study co-author Alan Cooper, of the University of Adelaide Australian Center for Ancient DNA, in a statement. "Something major happened, and the hunt is now on to find out what that was."

The new study also confirms that people sweeping out from Turkey colonized Europe, likely as a part of the agricultural revolution, reaching Germany about 7,500 years ago.

For decades, researchers have wondered whether people, or just ideas, spread from the Middle East during the agricultural revolution that occurred after the Mesolithic period.

To find out, Cooper and his colleagues analyzed mitochondrial DNA, which resides in the cells' energy-making structures and is passed on through the maternal line, from 37 skeletal remains from Germany and two from Italy; the skeletons belonged to humans who lived in several different cultures that flourished between 7,500 and 2,500 years ago. The team looked a DNA specifically from a certain genetic group, called haplogroup h, which is found widely throughout Europe but is less common in East and Central Asia.

The researchers found that the earliest farmers in Germany were closely related to Near Eastern and Anatolian people, suggesting that the agricultural revolution did indeed bring migrations of people into Europe who replaced early hunter-gatherers.

But that initial influx isn't a major part of Europe's genetic heritage today.

Instead, about 5,000 to 4,000 years ago, the genetic profile changes radically, suggesting that some mysterious event led to a huge turnover in the population that made up Europe.

The Bell Beaker culture, which emerged from the Iberian Peninsula around 2800 B.C., may have played a role in this genetic turnover. The culture, which may have been responsible for erecting some of the megaliths at Stonehenge, is named for its distinctive bell-shaped ceramics and its rich grave goods. The culture also played a role in the expansion of Celtic languages along the coast.

"We have established that the genetic foundations for modern Europe were only established in the Mid-Neolithic, after this major genetic transition around 4,000 years ago," study co-author Wolfgang Haak, also of the Australian Center for Ancient DNA, said in a statement. "This genetic diversity was then modified further by a series of incoming and expanding cultures from Iberia and Eastern Europe through the Late Neolithic."

Some of Europe's earliest inhabitants mysteriously vanished toward the end of the last ice age and were largely replaced by others, a new genetic analysis finds.The finds come from an analysis of dozens of ancient fossil remains collected across Europe.

The genetic turnover was likely the result of a rapidly changing climate, which the earlier inhabitants of Europe couldn't adapt to quickly enough, said the study's co-author, Cosimo Posth, an archaeogenetics doctoral candidate at the University of Tübingen in Germany. The temperature change around that time was "enormous compared to the climactic changes that are happening in our century," Posth told Live Science. "You have to imagine that also the environment changed pretty drastically."

A twisted family tree

Europe has a long and tangled genetic legacy. Genetic studies have revealed that the first modern humans who poured out of Africa, somewhere between 40,000 and 70,000 years ago, soon got busy mating with local Neanderthals. At the beginning of the agricultural revolution, between 10,000 and 12,000 years ago, farmers from the Middle East swept across Europe, gradually replacing the native hunter-gatherers. Around 5,000 years ago, nomadic horsemen called the Yamnaya emerged from the steppes of Ukraine and intermingled with the native population. In addition, another lost group of ancient Europeans mysteriously vanished about 4,500 years ago, a 2013 study in the journal Nature Communications found.

But relatively little was known about human occupation of Europe between the first out-of-Africa event and the end of the last ice age, around 11,000 years ago. During some of that time, the vast Weichselian Ice Sheet covered much of northern Europe, while glaciers in the Pyrenees and the Alps blocked east-west passage across the continent.

Lost lineages

To get a better picture of Europe's genetic legacy during this cold snap, Posth and his colleagues analyzed mitochondrial DNA — genetic material passed on from mother to daughter — from the remains of 55 different human fossils between 35,000 and 7,000 years old, coming from across the continent, from Spain to Russia. Based on mutations, or changes in this mitochondrial DNA, geneticists have identified large genetic populations, or super-haplogroups, that share distant common ancestors.

"Basically all modern humans outside of Africa, from Europe to the tip of South America, they belong to these two super-haplogroups that are M or N," Posth said. Nowadays, everyone of European descent has the N mitochondrial haplotype, while the M subtype is common throughout Asia and Australasia.

The team found that in ancient people, the M haplogroup predominated until about 14,500 years ago, when it mysteriously and suddenly vanished. The M haplotype carried by the ancient Europeans, which no longer exists in Europe today, shared a common ancestor with modern-day M-haplotype carriers around 50,000 years ago.

The genetic analysis also revealed that Europeans, Asians and Australasians may descend from a group of humans who emerged from Africa and rapidly dispersed throughout the continent no earlier than 55,000 years ago, the researchers reported Feb. 4 in the journal Current Biology

Time of upheaval

The team suspects this upheaval may have been caused by wild climate swings.

At the peak of the ice age, around 19,000 to 22,000 years ago, people hunkered down in climactic "refugia," or ice-free regions of Europe, such as modern-day Spain, the Balkans and southern Italy, Posth said. While holdouts survived in a few places farther north, their populations shrank dramatically.

Then around 14,500 years ago, the temperature spiked significantly, the tundra gave way to forest and many iconic beasts, such as woolly mammoths and saber-toothed tigers, disappeared from Eurasia, he said.

For whatever reason, the already small populations belonging to the M haplogroup were not able to survive these changes in their habitat, and a new population, carrying the N subtype, replaced the M-group ice-age holdout, the researchers speculate.

Exactly where these replacements came from is still a mystery. But one possibility is that the newer generation of Europeans hailed from southern European refugia that were connected to the rest of Europe once the ice receded, Posth speculated. Emigrants from southern Europe would also have been better adapted to the warming conditions in central Europe, he added.

Some 5,000 years ago, silver mining on the shores of the Aegean SeaAn exceptional archaeological discovery at Thorikos (Greece)

The team of mining archaeologists was supervised by Prof. Dr Denis Morin of the University of Lorraine, connected with the UMR CNRS 5608 (UMR National Center for Scientific Research 5608) of Toulouse. The scientists employed a drone to locate above-ground installations connected to the mining. It is the first time that such complex mining infrastructure is studied.

These subterranean investigations are part of a larger archaeological research program on the site of Thorikos directed by Prof. Roald Docter of Ghent University under the auspices of the Belgian School at Athens, the University of Utrecht and the Ephorate of Eastern Attica.

Denis Morin on this discovery: "today, it is difficult to imagine the extreme conditions in which the miners had to work in this maze of galleries. A smothering heat reigns in this mineral environment. The progress of the underground survey requires a constant vigilance in this stuffy space where the rate of oxygen must be permanently watched. Tool marks on the walls, graffiti, oil lamps, and crushing areas give evidence of the omnipresent activity of these underground workers. The hardness of the bedrock and the mineralizations show the extreme working conditions of these workers, for the greater part slaves, sentenced to the darkness and the extraction of the lead-silver ore ... Mapping these cramped, complex and braided underground networks, the ramifications of which are sometimes located at several levels, represent a real challenge in scientific terms". Underground, the morphology and the organization of the mining infrastructure allow to distinguish several phases of activity.

The archaeological data gathered and observed during the latest phase of the 2015 campaign: pottery, stone hammers made of a volcano-sedimentary rock quarry, point towards a high dating for the earliest phase of mining activities in the area (Late Neolithic / Early Helladic: around 3200 BC). If future research confirms this hypothesis, the chronological framework of mining in the region of Attica and the Aegean world would be profoundly modified. The Classical phase is by far the most perceptible; omnipresent, it is remarkable by the regularity of the sections of divided galleries that cover the whole space. Fragments of pottery and oil lamps, and even a Greek inscription engraved on a wall, testify to the activities in this period. Conduits cut with pointed tools, of quadrangular shape, cutting of the rock in successive stages, such are the characteristics of these particularly well organized mining works.

This resumption of the works at the end of Classical period (4th century BC) is dated by the tool marks in the galleries and the ceramic remains. Shafts discovered inside this network connect two main levels of mineralization's, and hence of extraction. Of perfect geometrical architecture, executed to the millimeter, their technique of construction is still investigated by the archaeologists.

Today, these shafts are only accessible using techniques of alpine caving. A certain number of these abandoned galleries has remained untouched over the last 5000 years. Others, which are now inaccessible, had been entirely banked up during successive phases of mining. Progressing in these galleries remains difficult for the experienced archaeologists, wearing high-tech equipment, in a stifling atmosphere with temperatures up to 21°C.

The mine that has been discovered in Thorikos is exceptional in its lay-out and extension. Up to now mining archaeologists working in the Laurion area did not explore such a complex network of galleries and mining infrastructure. They show the physical capacities and skills of the ancient miners to exploit these complex ore deposits and to assure ore dressing activities outside the mine from the Prehistory on. It testifies to a deliberate strategy and to perfect technological and spatial control over the process: an exceptional concentration of means to extract silver and a sophisticated technical system that in its scale is unique within the ancient world.

Already exploited since the 4th / 3rd millennium BC, by the 5th and 4th centuries BC these silver mines constituted the most important mining district of Greece, laying at the basis of Athens' domination of the Aegean world.

The 2015 underground survey campaign brought new information on the mining techniques developed since the first metal ages in this strategic zone of the eastern Mediterranean. The ongoing research not only aims to survey these subterranean remains, but it will also allow to understand the mining technologies of these early periods, the management of mineral resources, their extraction and processing as well as the circulation of the end products... These achievements of human ingenuity already foreshadow the technological advances of the Middle Ages. http://www.eurekalert.org/pub_releases/2016-02/gu-s5y021016.php

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The position of the ancient deme of Thorikos was located on the hill Velatouri on the edge of the plain of modern Thorikos, near the sea. Among the oldest ancient demes of Attica, Thorikos was one of the 12 settlements (komai) that, according to tradition, took part in the political unification under Athens (synoikismos) by Theseus. Due to its proximity to the mines of Lavrion, Thorikos was the mining centre of Lavreotika region. The site was inhabited from the Neolithic age (ca. 4500 BC) and without interruption until the 1st century BC.The excavations have brought to light part of the prehistoric settlement, as well as an extensive part of the historical deme, namely residential quarters, cemeteries, the theater, and the so-called "industrial quarter", along with ancient mines. It is noteworthy that mine extraction in Thorikos dates back to around 3000 BC. After the exhaustion of the mines of Lavrion and the destruction of Thorikos by the Roman general Sulla in 86 BC the area was abandoned temporarily. It was reinhabited during the Roman period until the 6th century AD, when the countryside of Attica was deserted due to the Slavic invasions. The archaeological research in the area was initiated by the Society of Dilettanti in the early 19th century. In 1886 the American School of Classical Studies conducted here its first excavation in Greece, followed in 1893-94 by the Archaeological Society of Athens. But with Thorikos has mainly associated its history the Belgian School at Athens. In 1963 commenced the archaeological exploration on the site which would last for decades, focused on the fortified acropolis, the theatre, the mines and ore plants of the 5th and 4th centuries BC.http://www.gtp.gr/TDirectoryDetails.asp?ID=14685

Velatouri Settlement Ancient Village or Settlement in Attica/Central Greecehttp://www.megalithic.co.uk/article.php?sid=15719The Velatouri hill is the centre of a Mycenaean settlement and the later ancient deme of Thorikos. An unusual 6th-4th century BCE theatre, parts of the settlement, some of the metal-working establishments, a 4th century BCE square tower, the cemeteries and the sanctuary of Demeter and Kore are Preserved.

The ancient theatre of Thorikos is noteworth for its unusual ellipsidal plan. The first excavations were carried out in 1820.

The dollar of that time, was used from Spain to Persia. One side represents goddess Athena and the other the owl, bird of wisdom. 390 BCE.

An ancient necropolis that once held more than 100 tombs from as far back as 4,000 years ago has been discovered near the Palestinian town of Bethlehem in the West Bank.

The burial ground was discovered in spring 2013 during the construction of an industrial park. In 2014 a team from the Ministry of Tourism and Antiquities of Palestine excavated some of the tombs, and in 2015 a joint Italian-Palestinian team surveyed the necropolis and created a plan for future exploration. The archaeologists found that the necropolis covered 3 hectares (more than 7 acres) and originally contained more than 100 tombs in use between roughly 2200 B.C. and 650 B.C.

Located on the side of a hill, the archaeological site — now called Khalet al-Jam'a — was likely a burial ground for a nearby settlement whose location is unknown...